Higher Number Of Scales Research Articles

A new Moenkhausia (Characiformes: Characidae) from rio Brao Norte, rio Tapajs basin, with comments on the fish endemism of Serra do Cachimbo plateau.

A new species of Moenkhausia is described from the rio Brao Norte, a tributary of Rio Teles Pires draining the Serra do Cachimbo, rio Tapajs basin, Par, Brazil. The new species is diagnosed from all congeners, except M. moisae and M. pirauba, by having a high number of scales in the longitudinal series (4346 vs. 2341 in other Moenkhausia species). It can also be distinguished from the aforementioned species based on the combination of the following characters: a single humeral blotch, 2125 branched anal-fin rays, and a round and symmetrical caudal blotch not continuous anteriorly with the dark midlateral stripe. The new tetra herein described represents an additional, possibly endemic, taxon from the headwaters draining from Serra do Cachimbo, in the Brazilian Shield.

A new species of cloud fish of the genus Hypsolebias from Northeast Brazil (Cyprinodontiformes: Rivulidae)

Abstract A new species of cloud fish of the genus Hypsolebias is described from a temporary pool in the rio Trairi basin, Rio Grande do Norte State, Brazil. It is the first record of the genus Hypsolebias for the basin. The new speciesbelongs to the H. flammeus species-group, which is composed of the species H. alternatus, H. brunoi, H. delucai, H. fasciatus, H. longignatus, H. marginatus, H. multiradiatus, and H. flammeus. The new species differs from all other species of the group, except H. flammeus, H. multiradiatus,and H. brunoi, by male color pattern and the presence of a metallic blue sheen surrounding the black spots of females. It differs from H. flammeus, H. multiradiatus and H. brunoi by dorsal and anal fin shape (both rounded vs. pointed) and by the orientation of the reddish-brown bars on the body and anal fin of males (diagonal vs. vertical). The new species differs from its congeners of Northeast Brazil mainly by the higher number of dorsal fin rays in males and the higher number of scales in the longitudinal series.

GPR clutter reduction by multi-resolution based tensor RPCA

ABSTRACT A new clutter reduction method which utilizes the multi-resolution and multi-directional information of the ground-penetrating radar (GPR) image is proposed. Sub-images obtained by stationary wavelet transform (SWT) or nonsubsampled counterlet transform (NSCT) are cast into a tensor structure presenting higher information compared to the spatial input data. A tensor-robust principal component analysis (TRPCA) algorithm is used for low-rank and sparse decomposition (LRSD) followed by inverse transform of the sparse tensor component to provide the clutter reduction results. The proposed methods TRPCA-SWT and TRPCA-NSCT are compared both visually and quantitatively to robust principal component analysis (RPCA) and TRPCA-bandpass filter (TRPCA-BPF), which employ the spatial raw GPR data and outputs of simple low-pass and high-pass filters respectively. Visual and quantitative results demonstrate that the clutter reduction performance increases when a higher number of scales and directions are used prior to the LRSD decomposition. Moreover, one of the proposed methods, TRPCA-NSCT, removes the background noise more efficiently due to its higher multi-resolution and multi-direction investigation capability, increasing the performance of the target detection algorithms.

Poly- and oligomerization of scales in the blue bream Ballerus ballerus (Cyprinidae) as a consequence of thyroid status regulation

Poly- and oligomerization of serial elements are among the ways to enhance, weaken or even change organ's function and might contribute to adaptation of animals. Involvement of thyroid hormones in development and formation of adult phenotype of scale cover was found recently. Cyprinid fish blue bream Ballerus ballerus has relatively high number of scales in lateral line (62–77) and may serve as appropriate object to examine the role of thyroid regulation of scale number in fish. Individuals kept under different hormonal conditions manifest highly differential number of scales. Experimental variation of scale number (49–114) broadly exceeds the limits of natural variation known for species. Goitrogen-treated fish have an increased scale number (polymerization), while triidothyronine-treated fish have a reduced scale number (oligomerization). Additionally fish of most prolonged retardation of development (goitrogen-treated) demonstrate phenotype of partially naked skin. This event of reduction of squamation and partial nakedness occurred due to underdevelopment. Also we suggest the regulation of the development by the thyroid hormones is thought to be a perspective approach to mark periods of determination of number of serial elements.

Una nueva especie de <i>Hyphessobrycon</i> (Characiformes: Characidae) de la cuenca del río Telembí, vertiente sur del Pacífico, Colombia

The genus Hyphessobrycon is included within the subfamily Tetragonopterinae. The species are generally small, do not exceed 70mm of standard length, are economically important as ornamental fish, with 128 valid species distributed from Southern Mexico to Rio La Plata in Argentina. The collections of fish were made with seines, in a single biotope, along shore in backwaters and working downstream. Measurements of the specimens were taken point to point with digital calipers. Observations of bone and cartilage structures were made on cleared and stained (C&S) specimens. The morphometric relationships between species were explored using a principal component analysis (PCA)using 21 variables. We described a new species, Hyphessobrycon chocoensis, from the Telembi River drainage of the Pacific versant of Colombia. The new species, Hyphessobrycon chocoensis, is distinguished from congeners not of the "flammeus" species group by: having a diffuse humeral spot, in lacking a dark spot on the dorsal fin and caudal peduncle. It is distinguished from members its species group by the number of rays in the dorsal fin (ii, 8, i), by the number of branched anal-fin rays (25-26) and by having a diffuse humeral spot. It differs from H. tortuguerae in the number of teeth on the maxilla (1-2), by the number of predorsal scales and the high number of scales between the lateral line and the anal fin (6-7). Hyphessobrycon chocoensis can be distinguished from the other known species of Hyphessobrycon from the Pacific Coast of Colombia in having: a high number of pored lateral-line scales, by the snout to dorsal-fin length, by caudal-peduncle depth and by eye diameter. In addition, it differs from H. columbianus by the distance from the dorsal fin to the anal fin, by the length of the upper jaw, and by snout length. It differs from H. condotensis in having a high number of scales between the lateral line and the dorsal fin, and by the number of simple rays in the anal fin. H. chocoensis is distinguished from H. sebastiani by the number of transverse scales and the number of scales between the lateral line and the dorsal fin. A taxonomic key is provided to aid with the identification of the species of Hyphessobrycon from the Pacific Coast of Colombia.

Hemiodus langeanii (Characiformes: Hemiodontidae), a new species from rio Amana, rio Maués-Açú drainage, Amazon basin, Brazil

Hemiodus langeanii, new species, is described based on 20 specimens collected in the rio Amana, a tributary of rio Maués-Açú, rio Amazonas drainage, Brazil. The new taxon can be distinguished from its congeners by its high body (27.1-35.3%, average 32.3% SL vs. 18.8-28.5% in remaining species). The new species also exhibits a large lateral dark spot that is equal to, or greater than, the eye diameter (vs. smaller in remaining species except for H. microlepis). The lack of conspicuous lateral stripe or transverse bands and the low lateral line scales count (68-74) distinguish H. langeanii from some similar species in the genus (scale counts: 94-123 in H. argenteus, 124-148 in H. microlepis, 86-99 in H. orthonops and 77-92 in H . parnaguae). Finally, the new species can be differentiated from H. unimaculatus (which overlaps in the number of lateral line scales) by the higher number of scales between the lateral line and the pelvic fin origin (9-10 vs. 4-7, respectively), which are similar sized above and below lateral line (vs. scales larger bellow the lateral line in H. unimaculatus).

A new bush anole (Iguanidae, Polychrotinae, Polychrus) from the upper Marañon basin, Peru, with a redescription of Polychrus peruvianus (Noble, 1924) and additional information on P. gutturosus Berthold, 1845

We herein describe a new colorful species of Polychrus with a conspicuous sexual dimorphism from the dry forest of the northern portion of Región de La Libertad, Peru. The new species differs from all other Polychrus species, in that this species has very small dorsal scales and thus a higher number of scales around midbody and in the middorsal line from behind the occipital scales to the level of the posterior edge of the thigh. Furthermore, we redescribe Polychrus peruvianus whose original description is short and lacks information on intraspecific variation and sexual dimorphism. Also, we add some information on intraspecific variation and ecology of Polychrus gutturosus. Finally, we synonymize Polychrus spurrelli Boulenger with Polychrus gutturosus.

Revalidation of Hepsetus cuvieri (Castelnau, 1861) (Characiformes: Hepsetidae) from the Quanza, Zambezi and southern part of the Congo ichthyofaunal provinces

Hepsetus cuvieri (Castelnau, 1861), originally described from “lac N'gami” (Botswana) and synonymized with H. odoe (Bloch, 1794) by Roberts (1984), is revalidated. Hepsetus cuvieri can be readily distinguished from H. odoe based on a lower total number of gill rakers (8–13 versus 14–21); a generally higher number of scales between the dorsal fin and the lateral line (10½–11½ versus 7½–10½) and a higher number of scales between the adipose fin and the lateral line (6½–7½ versus 4½–6½) and other characters. A neotype is designated, as the holotype of this nominal species is apparently lost. Hepsetus cuvieri is restricted to the Quanza, Zambezi ichthyofaunal provinces and the southern part of the Congo Basin, i.e. the Congo ichthyofaunal province.

Geographic Variation in the Emerald Treeboa, Corallus caninus (Squamata: Boidae)

Abstract The arboreal boa Corallus caninus is widely distributed across northern South America (the Guianas and Amazonia). We examined geographic variation based on examination of 192 specimens from throughout the range, and revised its taxonomy on the basis of quantitative and qualitative analyses of morphological characters (meristics, morphometrics, and color patterns). Based on the high number of lateral blotches on the body and the high number of scales across the snout, populations south of the Rio Amazonas and west of the Rio Negro are identified as a species (or, potentially, a species complex) separate from C. caninus, and the name Corallus batesii is resurrected for those populations. The distribution of Corallus caninus is restricted to the Guiana Shield (north of the Rio Amazonas and east of the Rio Negro).

A new arboreal Lepidodactylus (Reptilia: Gekkonidae) from Espiritu Santo Island, Vanuatu: from egg to holotype

Lepidodactylus buleli is a new gecko from Espiritu Santo Island, central Vanuatu, Melanesia. This species most closely resembles L. pulcher from Admiralty Islands (Papua New Guinea) by its elevated number of midbody scale rows, and belongs to Brown and Parker’s (1977) Group II based on having an entire terminal scansor on all digits followed by two or three divided or deeply notched subterminal scansors on digits II–V. It differs from other Group II species in having the following combination of character states: a high number of scales around midbody, relatively weak dilation of digits, slight webbing of toes III and IV, cloacal spurs, and an original coloration. This species lives in myrmecophilous plants hanging high on trees in the deep primary forest on the west dry coast of Espiritu Santo Island. It also is the first lizard known from a holotype collected as an egg in the field, hatched in captivity, and grown until reaching adult size, allowing its description.

Rivulus uakti sp. n. and R. amanapira sp. n. (Teleostei: Cyprinodontiformes:Rivulidae): two new species from the upper Rio<br />Negro, Brazilian Amazon

Rivulus uakti, new species, and R. amanapira, new species, from the upper rio Negro drainage, Amazonian basin, northern Brazil, are described. Both species are members of an assemblage, herein denominated R. atratus species group, that includes R. atratus, R. ornatus, R. rectocaudatus, R. romeri and R. tecminae, and is diagnosed by a unique pattern of frontal squamation and a derived color pattern of infraorbital region. The two new species seems to be closely related to R. romeri and R. tecminae by the absence of dermosphenotic and preopercular canal. Rivulus uakti is similar to R. tecminae and R. altivelis by having long pelvic fins, and differs from them by the fewer scales on the longitudinal series and a distinct female color pattern. Rivulus amanapira, similar to R. tecminae and R. rectocaudatus by having a truncate caudal fin in males, is diagnosed by the higher number of scales on the longitudinal series and unique color pattern of males.

A new species of gobiid fish, Cristatogobius rubripectoralis , from Australia

A species of the gobiid genus Cristatogobius from northeastern Australia is described as new. This species is distinguishable from other species of the genus in having a higher number of scales in a longitudinal row and in a transverse row and a rounded caudal fin. In addition, there are differences in coloration such as brown reticulation on the upper anterior part of body and a red pectoral fin. A species of Cristatogobius reported from S. Java, Indonesia, is also identified as this species.

The Genus Ogma (Criconematidae-Nematoda) in Australia

Species of criconematids formerly in the genus Pateracephalenema are transferred to the genus Ogma. Four new species and two new subspecies of Australian Ogma are described. Ogma feckneri n. sp. is distinguished from other described species by the long bare tail. O. sassafras n. sp. differs from related species by the longer stylet, larger number of body annules, more posterior excretory pore and higher number of annules from vulva to tail terminus. O. haguei n. sp. diifers from related species in tail shape, stylet length, number of body annules and position of vulva. O. bellum n. sp. is distinguished by the widely expanded lip region, greater number of scales per annule, and fewer body annules. O. civellae whianus n. ssp. may be distinguished by the single lip annule, and the very long stylet. O. civellae arboreum n. ssp. is characterised by the deeply fringed first annule, and the higher number of scales per annule. Further information is given about O. alticolum and O. australe. As a result of the transfer of Pateracephalanema australe to Ogma, 0. australis Andrassy becomes a junior homonym of O. australe Colbran and is therefore renamed O. andrassyi n.n. A checklist of species recorded in Australia is provided.